1. Field of the Invention
This invention relates to a button made of metal, and particularly to a button of which at least a button back is manufactured from aluminum or an aluminum alloy in order to manufacture the button at low cost and simply.
2. Description of the Prior Art
A button of the type in which a fastener called a prong having projected leg members pierces cloth to which a body of the button is attached from the back of the cloth and these leg members are fixedly secured to the button body to attach the button to the cloth is known from old times, as disclosed in U.S. Pat. No. 1,463,236 and U.S. Pat. No. 1,378,108. In the case of a metal button, generally such type of button is adopted.
The conventional metal buttons include, for example, a button 1 which comprises a button body 10 containing an insert (accommodated member) 11 surrounded by an outer shell member 13 consisting of a cap 14 and a button back 15 and a fastener 20 called a prong (tack) to be arranged so as to nip the cloth 30 between the button body and the fastener and having two leg members 21, as shown in FIG. 1 and FIG. 2, wherein the button is attached to the cloth by making the prong 20 to pierce the cloth 30 so as to make a hole in the bottom of the button back 15 and simultaneously to be bent (curled) by the aid of a curved surface of a recess 12 of the insert 11 so that it is fixedly secured to the button body 10 (hereinafter referred to as a metal button (A)); and a button 1a which comprises a button body 10a containing an insert 11a made of resin of which upper and side surfaces are surrounded by an outer shell member consisting of a cap 14a and a button back 15a and a prong (tack) 20a having a single leg member 21a of the arrowhead shape, which is to be arranged so as to nip the cloth between the button body and the prong, as shown in FIG. 3, wherein the button is attached to the cloth 30 by making the prong 20a to pierce the cloth 30 and press-fitting the arrowhead-like leg member 21a into a hole 12a of the insert 11a made of resin so that it is fixedly secured to the button body by the aid of the anchor effect of its leading end (hereinafter referred to as a metal button (B)).
In both the metal button (A) and the metal button (B), the above-mentioned caps 14 and 14a which have been used are either one of the followings:
(1) the cap manufactured by cold pressing a linear material of a copper-zinc alloy to a predetermined shape and subjecting it to various plating treatments from the viewpoint of its design,
(2) the cap manufactured by cold pressing a linear material of an aluminum alloy to a predetermined shape and subjecting it to an alumite treatment (an anodic oxidation treatment) from the viewpoint of its design, and
(3) the cap manufactured by cold pressing a linear material of stainless steel to a predetermined shape.
The inserts 11 and 11a are the parts to be built into the inside of the button body for the purpose of absorbing the shock at the time of attachment of the button, guiding the leading end parts of the prong leg members at the time of bending (curling) thereof, and preventing the prong leg members from being left out. In the case of the metal button (A), either of (1) the insert manufactured by cold casting iron or low-carbon steel into a predetermined shape or (2) the insert manufactured by molding a zinc alloy into a predetermined shape by die casting has been used. On the other hand, in the case of the metal button (B), the insert manufactured by injection molding a resin into a predetermined shape has been used.
Furthermore, in both the metal button (A) and the metal button (B), the button backs 15 and 15a which have been used are either of (1) the button back manufactured by cold pressing a plate material of a copper-zinc alloy to a predetermined shape and subjecting it to a silver white plating treatment from the viewpoint of its design or (2) the button back manufactured by cold pressing a linear material of stainless steel of which alloy color tone is silver white to a predetermined shape.
Generally a metal button is attached to such cloth as jeans and trucker jackets or denim jackets. Most of the button backs have the color tone of silver white so as to make a high-grade impression etc. on people. In order to secure the required fixing strength so that the above-mentioned button back may certainly not come off the cloth after completion of attachment thereof to the cloth by the aid of the prong, either of (1) a copper-zinc alloy subjected to silver white plating or (2) stainless steel having the alloy color tone of white is used. However, since the above material (1) has the alloy color tone of yellow, the high-grade impression is inferior to the whitish materials. Accordingly, the above material should be subjected to a silver white plating treatment to produce the high-grade impression. However, the plating treatment increases the working steps and will exert a harmful influence on a human body depending on the kind of plating. Moreover, there is a possibility of polluting environment due to a waste water treatment, for example, accompanying the plating treatment (environment load is large). On the other hand, as for the above material (2), since the alloy color tone of stainless steel material is silver white, there is no need to purposely perform the plating treatment of silver white. However, since its workability of cold pressing is inferior to a copper-zinc alloy, the life of a pressing mold is short, which requires frequent exchange of the metal molds, and the load exerting on environment is large.